Calling Alice Cooper glam might be the biggest insult i've ever seen on this board. He had some influence on the genre because of his look, but if you knew anything about his music, you would know it has very little in common with glam metal.
How exactly is Def Leppard glam? I've always considered them just a rock band. They never wore make up and Rick and Steve were the only ones with big hair so they didn't fit in to the whole Hair band label either. The same with Bon Jovi, Skid Row, GnR and Motley Crue, they're just rock bands. With Crue you could make an argument that they were glam on those first couple albums with all the makeup and looking like females thing they had going on. But starting with Girls, Girls, Girls they ditched that whole look and have never looked back since. Songwise, they're just a hard rock band
Van Halen sure as hell isn't one either.